R. T. Hill — The alleged Jurassic of Texas. 451 



the Canadian Valley and Tertiary of the Llano Estacado, 

 which he called Triassic and Jurassic respectively, and no- 

 where touched upon the Cretaceous in the State of Texas. 

 Professor Marcou by his writings has at several times conveyed 

 the impression that he had seen the Cretaceous in Texas.* The 

 various journals, itineraries and maps of the Pacific Railway 

 Expedition as published by himself and others, giving a minute 

 record of the progress of the party day by day, show that it 

 nowhere encountered this locality or any other south of the 

 Ouachita Mountains. The fossils from Fort Washita and the 

 Cross Timbers of Texas described by him in his Geology of 

 North America, were collected and sent to him by Dr. Gr. G. 

 Shumard. 



Each of his localities have since been thoroughly studied by 

 specially equipped expeditions of the United States Geologi- 

 cal Survey and the Texas State Geological Survey. The Tu- 

 cumcarri region lias been twice visited by me and the results 

 of my observations published in Sciencef and in this Journal;}; 

 and elsewhere.§ | The Texas Geological Survey also made 

 researches in this locality > and published extensively thereon. ^f 

 Professor Alpheus Hyatt several years ago spent a season of 

 minute field work upon the region, and his manuscript report 

 thereon is in the office of this Survey. Thus we have, as 

 opposed to the three hours spent by Professor Marcou, the 

 observations of three independent parties, who have devoted 

 days and months to the locality. Each of these parties 

 (although both Professor Hyatt** and myselfft were at first pre- 

 disposed towards Professor Marcou's conclusions, and made the 

 mistake in print of partially supporting him) have all arrived, 

 after careful and impartial study, at conclusions contrary to 

 his. I have shown beyond all doubt that the deposits which 

 he called Jurassic are Cretaceous — not only Cretaceous, but of 

 a Cretaceous horizon which I believe to be of the same general 

 formation but of a horizon strati graphically above the rocks 

 which he, himself, collected at Comet Creek and ccdled " JVeo- 

 comian" It is also extremely doubtful if the Comet Creek 

 beds are homotaxially equivalent to the Neocomian, as he 

 alleges. 



* "I have seen and studied the strata of the Upper Greensand and Marly 

 Chalk, in the bed of Little River," etc., "and also on the Kim Fork of Trinity 

 river" — Professor Marcou in American Geologist, August, 1894, p. 100. 



f July 14, 1893. 



% September, 1895, p. 234. 



§ Report on Underground Waters, Washington, 1892. 



|| Bull. Geol. Soc. Amer., May, 1894, p. 332. 



"j[ Third Annual Report, pp. 201 et seq. — A controversial article fully answered 

 in Science, July 14, 1893. 



** 11th Annual Report U. S. Geological Survey, Part 1, pp. 9?-100. 



ff Circular letter, Austin, Texas, 1888. 



